As control devices at opening/closing sections for opening/closing windows that are opening/closing sections of vehicles, electric window devices are put to practical use. Further, safety devices are invented and are put to practical use so that, while the window is being closed by the electric window device, exertion of a great power is prevented due to the possibility of pinching a foreign object such as a body. Patent Document 1 (Japanese Patent Application Laid-Open No. 2007-126960) describes that a variation of a rotating speed is calculated based on a current value and a past value of a motor rotating speed, and a pinch is detected by using the variation.
FIG. 9 is a diagram describing a constitution of a conventional electric window device 90. The electric window device is constituted by connecting an operation switch 93, a motor driving circuit 94, motors for respective windows 95 . . . , rotary encoders 96 . . . , load sensors 97 . . . , temperature sensors 98 . . . and acceleration sensors 99 . . . to an electric window control section 92 connected to a battery 91 of a vehicle. 100 is a power steering control section.
The electric window control section 92 outputs a signal to the motor driving circuit 94 so that power is supplied to the motor 95 provided to a window specified by input of the operation switch 93, and the motor driving circuit 94 supplies power to the motor 95. At this time, the rotary encoders 96 rotate, and the electric window control section 92 inputs the signal from the rotary encoder 96 so as to obtain a rotating speed of the motor 95 and calculates a displacement of the window opened/closed by the motor 95, and performs feedback control. In addition, in the case where the occurrence of a pinch is detected by comparing past rotating speeds and rotating positions of the motor 95 that are preliminarily stored, for example, the motor 95 is reversely rotated so that danger can be avoided.